Mustang Brake Control/Line Lock

Anyone who has ever done a burn out can more than appreciate the benefits that a Line Lock can provide. Using a button to control the front brakes not only makes life easier on the rear brakes, but also makes control of the car much easier. At the same time, the additional control that a Line Lock provides in staging is also a major benefit.

A Mustang Line Lock is an electronic solenoid that controls a valve which is in line with the front brakes. Normally, the valve is open and allows fluid to pass through to the front brakes as usual. However, while the front brakes are applied and the solenoid is activated, the valve closes to trap the fluid in the front brakes keeping them applied until the control is released. It’s a simple process which requires a very straight forward install. Also, with its relative low cost, it’s something that just about any racer should consider.

Where to start:

The first thing you will need to do is determine how you will route your brake lines. On rear wheel drive cars you will be working with the lines to the front brakes as these are the ones you will want to keep locked when you are doing your burn out. With some cars, the two front brake lines are joined at the proportioning valve or just after it. For these cars the install will be very easy as all you need to do is send the line from the master cylinder over to the input of the Line Lock, and then from the output of the Line Lock back down to the Proportioning block. On other cars, such as most Mustangs, both front brake lines originally go directly to the master cylinder, although one line typically comes through the proportioning valve first.

With these cars, you will need to plug off one of the two front brake connections on the master cylinder, usually the lower one. The remaining connection will then go over to the input of the Line Lock. From the output of the Line Lock, you will then have a few options. With some Line Locks, such as the Hurst Roll Control, you can use the body itself as a “T” to join the two front brake lines. The other option, especially for those not using a Hurst unit, will require the two front brake lines to join at some other point, either at or before the proportioning valve.

Brake Control

As these images show, you can mount the Line Lock just about any way you want. All you have to do is run one line from the master cylinder and one back to the factory proportioning valve. At that point, you can split things up any way you need. Some put a “T” fitting before the proportioning valve, and some use the valve itself as the “T.” Also, for best results, you will want to keep the lines and the Line Lock itself away from any excess heat. Too much heat in the system will hinder braking performance. Also, once you’re finished with all the brake lines, you will need to bleed the braking system. This part is very important as you don’t want to find out as you’re rolling out the driveway that you have no brakes.

Line Lock

Wiring it up:

A Line Lock can be as easy to wire up. If you want to keep it extremely simple, you can ground one half of it, and run the other wire off to a switch inside the car, perhaps on the shifter. However, if you want the best results, you will want to make sure you at least use a relay to power it. On the other hand, if you want to get a little more technical with your install, you may want to do something a little different. Most of my installs use a single switch to turn on and off all the accessories I want to use at the track. This mode switch turns a relay on and off that powers any of the other “race” accessories, such as the Line Lock, Nitrous System, Shift Light, etc… I also like to wire up the Line Lock to work off the factory horn button.

Line Lock

When the switch is off, the horn works like it normally does. When the mode switch is on, the horn button activates the Line Lock. This way you don’t have a ton of switches all over the car, and it keeps the install looking clean. It also puts the control of the Line Lock (the horn button) in a very convenient place. This way you can activate it with the hand that would already be on the steering wheel, while allowing the other hand to stay on the shifter. Either way, I find this method to be a great way to handle things.

Using the Line Lock:

When using a Line Lock, the first thing you will need to do is apply the brakes. For best results, you may want to pump them once or twice before you really mash the pedal to the floor. With the brakes applied, you will now want to hit the Line Lock control button. This will lock the front brakes closed allowing you to let off of the brake pedal with your foot. As long as you hold the button, the front brakes will stay locked. As soon as you release the button, the front brakes will release and the car will again be allowed to roll. While all this makes doing a burn out a little easier, both on the car as well as the driver, don’t forget that its also very helpful in keeping the car in place once you’re staged. Either way, this is definitely one thing that every car that hits the drag strip on a regular basis should have.

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